| 1. |
- Gomez, Federico, et al.
(författare)
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Biochemical aspects of carrot processing
- 2003
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Ingår i: International Symposium on Future Technologies for Food Production and Future Food Scientists, Proceedings. - 0280-9737. ; :162, s. 87-87
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Konferensbidrag (refereegranskat)
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| 2. |
- Gomez, Federico, et al.
(författare)
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Factors affecting quality and postharvest properties of vegetables: Integration of water relations and metabolism
- 2004
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Ingår i: Critical Reviews in Food Science and Nutrition. - : Informa UK Limited. - 1040-8398 .- 1549-7852. ; 44:3, s. 139-154
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Tidskriftsartikel (refereegranskat)abstract
- Growing of vegetables in the field, harvesting, handling in the packing house and storage are events in the lifetime of vegetables that arc analysed from the point of view of the complex series of physiological transitions taking place in each of these events. Water is the major factor limiting plant metabolism and plants have developed fascinating mechanisms to cope with this limiting factor. Therefore, water relations (water, pressure and osmotic potential) are used as criteria for discussing plant stress physiology aspects such as osmotic, elastic adjustment and cold acclimation, as well as mechanical stress when the vegetable is harvested and during handling in the packing house. Consequences for the storage potential and quality of the vegetable arc discussed. After harvesting, the postharvest cell has the ability to complete a complex series of physiological transitions that will influence vegetable quality and further processing operations. Metabolic changes in the cytosol, cell membrane and cell wall are described.
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| 3. |
- Gomez, Federico, et al.
(författare)
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Influence of cold acclimation on the mechanical strength of carrot (Daucus carota L.) tissue
- 2004
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Ingår i: European Journal of Horticultural Science. - 1611-4434. ; 69:6, s. 229-234
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the influence of cold acclimation on the mechanical strength of carrot (Daucus carota L.) taproots. Changes in the mechanical strength were monitored when cold acclimation was induced in carrot plants cultivated in a growth chamber under strict climate control and in taproots harvested from field cultivation, where the plants had been exposed to the natural variations in climate. The appearance and accumulation of an antifreeze protein in the cell wall isolated from cold-stored taproots showed that a cold acclimation process is in progress in the harvested taproot derived from carrot plants grown in the field. The force needed to slice the taproots significantly increased during the first 12 weeks of storage, where the higher concentration of the antifreeze protein indicated the highest development of cold acclimation during that period of time. The increase in tissue rigidity during cold acclimation was also shown by the increase of the Young's modulus in taproot tissue from carrot plants acclimated 11 weeks under controlled temperature conditions. After 24 weeks of storage there was a significant increase in slicing force that was accompanied by signs of cell membrane deterioration, as measured by relative electrolyte leakage. Thus, the later increase in tissue strength might be related with a senescence process.
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| 4. |
- Herppich, W B, et al.
(författare)
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Effects of temperature and water relations on carrots and radish tuber texture
- 2004
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Ingår i: Journal of Applied Botany and Food Quality / Angewandte Botanik. - 1439-040X. ; 78:1, s. 11-17
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Tidskriftsartikel (refereegranskat)abstract
- Tissue firmness and stiffness are functions of tissue and cell wall structure, water status and temperature, and their interactions. This investigation elaborates the physiological basics of temperature and water status effects on firmness of fresh intact carrots and radish tubers. The results can add to a better understanding of the mechanical properties at least of these succulent plant storage organs. Water potential of intact carrot roots and radish tubers was measured with a pressure bomb, firmness was determined as the force necessary to cut the entire tuber perpendicularly to the length axis with a microtome knife adapted to a universal testing machine, and osmotic potential psychrometrically in expressed tissue sap. Hence, volume averaged pressure potential or turgor could be calculated from water potential and osmotic potential data. Water potential and turgor were positively correlated with cutting force in both species. Beyond wilting, the variation of cutting force with declining water potential was less pronounced. In carrot but not in radish tubers, cutting force and turgor were higher at lower tissue temperature (ca 10degreesC compared to ca 20degreesC). On the other hand, temperature did not influence the relationship between water status and texture in radish. In contrast, tuber development led to an increase in cutting force. From the presented results it seems obvious that the temperature effect on cutting force in carrots is mediated by affecting cell wall properties and not water status.
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